The present invention is a hydraulic linear impact tool which does not employ the accumulators normally used in the past (e.g. U.S. Pat. No. 3,971,448). During the impact stroke, there is no flow of fluid in the supply and return lines as is the case with devices which use accumulators. This is important in that the impact speed (force) and frequency of impacts are effected, in the devices employing accumulators, by the size of the supply and return lines. The lines are also subject to high pressure excursions which can cause damage. In the present invention, impact speed is not affected by supply and return line size because no flow of fluid occurs therein during the impact stroke.